Information for HRIBF PAC-13 Proposals

mass difference calculator	Estimate isobar contamination
TOPS	Estimate tandem voltage and beam charge state(s)
RIB yields	Measured or estimated yields
Velocity calculator	Time-of-flight or Doppler shifts

We encourage you to contact us with suggestions for the beams you require to pursue your physics research. Parameters as to what constitutes a suitable beam for the HRIBF may be found in our more recent newsletters.

We ask that you be aware that scheduling experiments at our facility is not straightforward; several experiments must be available before there is "critical mass" so that it is cost effective to schedule a particular RIB ion source or endstation configuration.

Additional information reflecting the present status of equipment and techniques is provided on our equipment web pages. You are encouraged to contact the mentor of the equipment should you have any questions. Information from previous PACs is provided below.

Ranging out for decay studies

We have begun using our ranging out technique of neutron-rich accelerated beams in RIB experiments. Significant reductions in Ga and higher Z contaminants are observed for neutron-rich Cu isotopes. Two modes of operation were attempted. By running the ion chamber at full range-out pressure, the reduction in Z ≥ Z+2 contaminants approaches 100% with a ~50% loss in the desired isotope. However, the beam spot is enlarged at the point of deposition which makes absolute measurements involving gamma radiation more challenging and yet, is beneficial to studies requiring time and position correlations in thick double-sided silicon strip detectors. By using the ion chamber at lower pressures, one can control the size of the beam at deposition and adjust the isobar separator to provide similar results. However, the performance of the isobar separator is dependent on the beam emittance and mass differences.

LeRIBSS

We hope to complete a new Low-energy Radioactive Ion Beam Spectroscopy Station in 2007. This beam line is located below the tandem (actually attached to the ceiling above the rotating energy-analyzing magnet) and will take mass-separated radioactive ion beams directly from the high-resolution magnet of the RIB injector. We should be able to use positive and negative ions from the RIB injector and we hope to have all the usual HRIBF decay spectroscopy equipment available. Proposals requiring this beamline will be considered by this PAC but may not be able to run until late in 2007.

Rotating target at RMS

A rotating target for decay studies at the RMS has been developed. Suitable for intense stable beams or even extremely delicate targets for radioactive beams (e.g. sulfur-compound targets), the stepper-motor assembly is located inside the vacuum chamber. Initial experiments with Fe beams on Ni targets have successfully used a factor of 2.5 higher beam current. A new DC motor coupled with slightly larger targets (14 mm diameter) is under development.